System and method of producing by means of combustion-engines, electric current.



w. A. T. MiiLLER. SYSTEM AND METHOD OF PRODUCING, BY MEANS OF COMBUSTION ENGINES, ELECTRIC CURRENT. APPLICATION FILED EAR. 29, 1909.

1,064,981 Patented June 17, 1913.

WITNESSES 'lklt/ENTUR NITED sra'rssrirrnnr oFFioE.

wnrmmvihnom-THEon'o R MULLER, or BERLIN-STEGLITZ, GERMANY.

iisYs'rnivr AND METHOD OF PRODUCING. BY MEANS OF COMBUSTION-ENGINES, ELECTRIC l CURRENT.

To all-whom it may concern BBS-1t known that l, \Vnainmr Anonr Tunoiuoi':MULLER, engineer, a subject ifierlin steglitz, Gern'iany. have "man Emperor, residingat- 5 "Means of Combustion llngines. Electric -Gurren tron of the invention, such as will Thisinvention relates to improvements l5" and I do hereby declare the fol full, clear, and exact descripenable 'othe-rs skilled in the art to which it appertainsto makeand use the same.

Loafing to be a in a: system and a method of producing, by 'means of combustion engines, electric current, thestrength and the voltage of which The improved arevery variable.

, method is particularly adap'ted foruse in the traveling dynamo sys-, "tem of electrically driven railless freight car "trains, in which the speed is regulated by changing the voltage of the system. In waderto decrease the losses in case of small loads, systems 'of this character are composed of a plurality of independent sets of machine, such "for example as benzin dynamos, (that is dynamos' ,which are directly coupled with bcnzin engines). Of these "sets of machines only' such a number is in "operation as is required to supply the necski.

- consists I in regulating the "essary'energy, the resistance of which energy is'd'ependenton the number of the freight cars and the'rcsistancc of the road.

The main object of the invention is to provide a system. whereby the said independent sets of generators included in'the same circuit are more readily controlled. so that one man can start and govern all the "generators.

further object of the improvements is to provide a system in which the apparatus required for controlling the system are' simplel while the operation of thetrain sate. Vit'h these objects in view theinvention amount of the energy suppliedby each s it,and"i.t,s direc- 't'ion'of'operation by varying the intensity of the exeiting" current of the ,dynamos the *zrr iiatiii'cs of which are connected in series, "alias hereinafter described? For 'the application of any i'nyention it is Ea]prerequisite.that the dynamo's be provided with a p' 'iropriate well linowirin ans, such as commutator poles or compensating coils, to

Specification of Letters Patent.

' Patented June 1'7, 1913.

Application filed March 29, 1909. Serial No. 486,407.

permit the regulation of the magnetic fields without rega rd to the armature fields. Furthermore. the method can not be applied, beforean electromotive force is produced in the system. Therefore, when stafting the systen'i, the first set of machines must be started by hand or in another suitable manner. However, the initial electromotive force required in the system can also be supplied hy a storage battery.

In. the accompanying drawing illustrating the invention applied by way of example to two cooperating benzin dynamos, I and II represent the two sets of machines, M'the bcnzin engines, and D the dynamos.

A is a switch-beard provided with projecting contacts a which are connected with the armature leads (shown in thick lines) and can be interconnected in various Ways by means of contact pieces I). In the position shown in the drawing, in which the contact piece b connects I with +II, the two arinatn re circuits are connected in series.

Preferably, the armatures. of the various sets of machines are connected in series from the beginning of the operation. and in this case means are preferably provided whereby the armature of each set can be short-circuitcd. in order to avoidlosscs of energy and heating of the armaturcs which are out of operation. \Yhilc the amount of energy reqnircd'is small. for example it only the car of the train which carriols the system is run, unit it is coupled to a single car. only one setof machines is in operation' To produce this result. one of the sets of the machines.

for instance. ll. can be disconnected by placing' anothcr contact piece I in the hosition t-ll. lll and when it" is desired to considerably incrcasc the supply (it current. the twodynamos arcconnected in parallel by using two contact pieces I in the positions (Fil -kill and (-l. 'lll. it. however,

several cars are to be coupled to the motor car in the course of its travel, or if a train 'of'the usual length. such for example as a train of sivcars, must travcl over steep roads. so that the amount of energy required rarics from a minimum (occurring on downgrades) to a maximum, the short-circuiting of ,tl1CttI'l\l1\flll'QS is removed, whereupon the improved method can. be employed.

"As soonlas the first set of machines is insuflicient to produce the amount of energy requiredthe-seo0nd one is thrown into opis done in a convenient and safe way. Main eration. At the beginning, the latter c0un tel-acts the effect of the first set, because it must be started, for which purpose its field excitation is so directed, that the dynamo produces a momentum for starting the benzin engine. The'leads shown in thin lines represent the field exciting circuit in which a two-pole switch U and a variable shunt resistance R are provided for each dynamo. Each of the said switches U can be moved on to three contacts referred to on the drawings as l, 2 and 3 respectively. The contacts 1 and 2 are connected by means of the leads 0 and d to the and poles in the manner indicated, so that when the contact lever of the switch U is on either of the contacts 1 and 2, the dynamo D receives its exciting current from one of the working machines, said current flowing in the one direction, when the contact lever is on the contact 1, and in theother direction, when the contact lever is on the contact 2. As soon as the engine being started is in operation, the direction of the field excitation is reversed, whereupon the second set supplies positive energy to the circuit. The same operation takes place, in further sets of machines, if such are provided. The field exciting current for the machine to be started can be taken from the set or sets which are already in operation, or from a storage battery. lVhen the contact lever is moved on to the contact 3, the exciting circuit is connected by the leads 6 and f with a source of cur-' rent (such as that shown at B) in order to start the excitation and thereby the operation of the first set of machines. By regulating the field exciting voltage of the individual-dynamos, the total effect of the system can be allotted to the sets of machines in any desired ratio, for example according tothe power of the individual combustion engines. As the working current is the same in all the armatures, the effect of the individual sets of machines depends exclusively on their field excitation. The latter controls the ratio of the total voltage supplied to the system by each set.

By the improved method, the sets of machines are started, and the load of the same is regulated exclusively by regulating the shunt field windings of the dynamos, which circuit resistances which in other systems are necessary for starting the machines are dispensed with. For regulating the workmg current from Zero to its maximum, or vice versa, only the Weak currents of the shunt circuits must be regulated, whereby the safety of the operation is considerably increased.

For changing the field exciting currents in the individual sets of machines after starting the system resistances are not required, but after connecting the field excitations to thqarmatui-e poles of their respective dynamos such changes can be made by changing the number of revolutions of the cooperating combustion engines, and by thereby changing the self excitation. For

practical purposes both methods of regulating the field excitations will be used.

The above described method can be used with good results in generator systems of the character referred to as long as the maximum current required is within certain limits dependent on the'size ofthe brushes of the dynamos. If, however, the intensity of the current required in the system is above this limit, the improved method is varied as follows: By changing the field excitations the operative machines are so regulated that the intensity of their current is zero, whereupon the armatures are connected in parallel, and their voltage is again raised. In this case, while the armatures are connected in parallel, the load of the individual sets of machines can not be regulated to the same extent as in the above described example in which the armatures are connected in series. Instead of the said regulation, the sets of machines are automatically regulated when connected in parallel, so that the energy system is almost uniformly distributed among the cooperating sets of machines. This automatic regulation is based on the fact, that high speed combustion engines, such for instance as automobile motors, in which the throttle valve is continuously, open, and which are not provided with a throttling speed regulator, upon a change of the momentum caused by an outer influence, change their speed, so that a definite speed corresponds to each momentum, a decrease of the momentum causing an increase, of the speed, and an increase of the l'llOlflClltlllll causing a decrease of the speed. If, therefore, the dynamos are connected in parallel, an increase of the load of one of the sets of machines as compared to the other sets .causes a decrease of the speed of the said set and therefore a decrease of the eleetromotiwe force of the same, and, vice versa, a decrtase of the load causes an increase of the electromotive force. The changes of the clectromotive forces cause corresponding changes of the intensity of the currents supplied by the respective sets in such a way that the load is balanced.

it is not necessary, that the excitation of all the. sets of machines be the same. If the excitation of one of the dynamos is too small, the voltage of the same is made equal to that of the other dynamos by automatic regulation of the speed. Should the fuel supply be stopped in one of the combustion engines, no damage can be done, because in such cases the armature current of the said dynamo is reversed. It will therefore be supplied by the rotated by the currentuntil the defect is ob- I served, whereupon the dynamo is either thrown out of the operation, or the defect is repaired. The automatic regulation can not take place without the objectionable balant-lug of the machines, unless the momentum of inertia of the revolving bodies is as small as possible. Therefore the sets, of machines must be composed of high speed combustion engines having no fly wheels and of dynamos which are directly coupled to the said combustion engines.

I claim:

1. A method of operating a current producing system or installation comprising a plurality of i units each consisting of a dynamo and an internal combustion engine coupled therewith, which consists in first starting one unit, exciting the fields of the successive dynamos to, cause them to actas motors and thereby start their respective engines, and then reversing the field excitations of said units when a predetermined speed is attained, substantially as described.

2-. A method of operating a current generating installation comprising a plurality of units each consisting of a dynamo and a prime mover coupled therewith, which con-' sists in first starting one unit, then exciting the field of another unit in such a direction as to cause the dynamo of said unit to act as.

a motor and start its engine, reversing the field excitation ct said unit.- after starting, to

r supply current to the line, and regulating 2 lo a travelin il'vnauio sistciii of electric traction, a current generating installation for the train comprising aplurality of generating units each of whichconsists of a dynamo and a prime mover coupled thereto, means to start one of the prime movers by temporarily using the dynamo of such prime mover as a motor by exciting its field from a suitable source, means to connect the dynamos in series or in parallel, means to reverse the field excitatio-ns of the dynamos, and means to regulate the? field of each dynamo to vary the energy supplied by the corresponding unit, substantially as described.

4. In a traveling dynamo system of eleccoupled together, said dynamos being of theshunt-wound type, means to start one-of said engines by exciting the field of its dynamo and thereby causing said dynamo to act as a motor, means to connect the armatures of the dynamos in series or in parallel, means to connect the field of an inactive dynamo to a dynamo already set in operation, in order to, excite such field in either direction, and means to regulate the excitation of each dynamo field to vary the amount of energy supplied by the corresponding unit, substantially as described. I

In testimony whereof I have atlixed my signature, in presence of two witnesses.

' WlLllELlll ADOLF THEODOR MULLER. 'it ncsses:

\Voiininuiu: llAUP'i, llENltY llasricii.

Copies of this patent may be obtained for cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

